Method of treating ore.



M; McMURRAY, B` '1. MULLl-IN & H. vPEPPEL. IyIETIIon oF TREATING ORE. .APPLICATION FILED ocT.`I4,`1913. l 1,183,891 Patented May 23,1916.

1 1 l l l 1 1 1 fr.

To all whom t may concern sTArEs I4ier-irENT MQNURRAY, o' cDnvELANnfAND BnNJAMrN a'. MULLEN AND HARRY Perrin.,` or LEETONIA, curo; SAID MULLEN AND sAID rnrrnn AssreNOns To UNITED IRON i. srEnnooMrANY, orcLEvELAND, omo, A cOnPOnAr-ION or rnNNsrLvANIA.

METHOD or TREATINQ onu.

Maasai..-

Bev it 4known tuant we, MAX MoMUnRAY,

BENJAMIMJ MULLEN, and HARRY PEPPEL,

citizens ofthe United States, residents, re-

spectively, offCleveland, county of Cuya# hoga, and State of Chim'. and Leetonia,

county of Columbiana, and State of Ghio, -,have invented anew and useful improve- -`ment in Methods of Treating Ore, of 'which the` following is a specication, the principle ofthe invention being hereinexplained and the best mode in which We have conteur- -plated applying that principle, so as to dis* `tinguish it from other inventions.

Our invention relates to methods Of treating ore and v' particularly s 'to methods of t treating ores which are in a finely divided v treatment, is called ti.-

4In the practice of'this process, the pulverulent line-dust is placed' upon a porous hearth or pulverulentlstate, such'. as, for instance,

Hue dust from blast furnaces. i

.The object of our invention is to provide a simple, economical and eicient method of treating-such pulverulent ore, whereby it may be given physical characteristics such as will,l render 1t amenable from a commercial' standpoint, to ordinary and well-known treatment designed to recover its valuable content.

-As is well-known to those skilled in the` art, one of the methods by which blast furnace flue-dust is rendered capable of vsuch ming-process.

suitably supported, ignited so as to start internal combustion, 'that is combustion ofthe coke dust and sulfur content, and such combustion maintainedby passing a current of air downwardly through the Ore mass. The temperature which results from .such combustion is such as will elfect a partial fusing I of the ore with a resultant agglomeration or sintering of the particles, so as tO produce i lumps of such character as will permit themthe latter.

In the bars. 'In addition,

to retain their integrity to such an; extent, 'as to render them suitable for forming part of the charge of blast furnace, and permit their values to be extractedbythe action of s interi-ng` prcess las at present practised, grate-bars are used to support the porous ,hearth and the temperature generated is such' as lto eventually burn out these it is necessary to em- I. Specication of Letters Patent.

raten/teu Mayes," 1916.

ploy means for creating lthe required aircurrent, 'which means usually 'consist of an exhaust fan or siphon. The ore mass is sometimes first molstened with water, as for instance, in al concrete mixer, whereupon it is placed upon its' porous bed and an air current caused to fiow therethrough. v The mass 1s then ignited by means of a gas fiame or by means of burning crude-'oil previously sprayed upon its upper surface. This initial lgnition shortly starts the combustion of the eolie-dust inthe mass and the sulfur of the iron-ore. allowed to continue until the conversion or smtermg is completed, whereupon the agglomerated mass is removed and broken up as desired. Y

The moistening of the dust, as above described, is resorted to in order to cause the particles to adhere to each other and perpass slowlyy the resultant product is more or less granular and unfused. If passed through rapidly, it becomes partially fused or sintered as is required. It is therefore essen` tial that the air be permitted p to pass' l through the mass with a certain amount of freedom, or in other words a certain degree of permeability be maintained` in the mass throughout the process.

v Itis also desirable, from the standpoint of economy, to carry out the process by reducing the volume ofair required to aminimum in order to operate the exhausting apparatus on as low a vacuum as possible, thereby reducing the amount of power con- Y sumed'to a minimum.

With -these main objects in view, our invention consists of va method hereinafter fully described and particularly set forth in the claims. v

The annexed drawing and the following description are used to set forthin detail a .certain method embodying' our inventlon,

The combustion so h initiated is .mit the material to be more advantageously handled as -well as to prevent it'- from too 75 Aj -the disclosed detailedmethod,however, con' -which the principle of the invention mayfbe rthe,y pan, which bed is supported b suitable grate-bars 2 having openmgs shown in dotted lines) therethroughl .through which the air may pass.r This porous bed is about one-halfinchin depth and usually consists of. limefstone screenings. Upon this bed is charged the; -pulverulent ore, previously, moistened 'or not, .as circumstances' may 'dictate. Below the grate-bars is an inclosed chamstitutingI but one of various methods j in employed.A

l.' In saidannexed drawing :-.-Figure l'is a plan-of a .well-known formof a-'sin'teringpanforming partfof the complete apparatus by means of which our grate bars carrying.

or hearth lis first formed inthe bottom of Aber 4 provided with outlets 5,5,-which are connected' with any .suitable exhausting ap paratus such as anexhaust fan or Siphon (not interstices which'existv in.- the mass and shown. The exhausting apparatus is now put'nto 'operationso as-to lcause an air cur-A rent to travel downwardlyy through all such through which the. air '-canfind its way and combustion initiated "as above described.

nishes sufficient yhe'atfor 4effecting the aglomeration or sintermg as -requlred and as as heretofore been obtained. l After the initial ignition has progressed sufici'ently to permit sinteringtobegin, in-

y stead of permitting such sintering to proceed Afrom this point on as has heretofore been the custom, we supply the'tmass throughout the remainder of the process, with water, orits equivalent, either continuously or intermittently, in suitable'amount, such amount de ending" upon thenature ofthe charge and eing determined empirically; This waterlls applied to thesurface of the ore by any suitable means, such asa-hose or ray, and' is at onceI converted-into steamiwhich along i-rst, it reduces 4the time requiredto convert. the "charge, from "twentyfive't'o fifty percent, according tov the 'nature of thema'- i terial to be converted.- Second, the resultant Aprod-uct is very mu'chm'ore. Uniform inrecess may bev` practised. Fig. 2 isa longitudinal section of suchpan., Fig'. 3 represents a side elevation, -upon a' reduced scale, 'of on e of the'- v out .our improved process, aslis '-now" the general' practice7 a porous bed y hence eliminated.- Sulicient heatis soon generated to ignite the coke-dust, if .any,:in the charge 'as -well as" the sulfur content' of the ore itself. The -continued combustion of these elements furcombustion,

-lplying then ldirectlyfupon the; ignited ore, 18, .9

case'. Third the'exhausting apparatus it is the gratears isv greatly retarded i not a1- together eliminated.

The first resultis obtained byl reason of the fact that thesteamis a-n element in establishing andl maintaining a more marked 'permeability than has heretofore been obtained, so that combustion is freer and completion of oxidatlon and sintering hastened. This probably accounts' for the -Ise'cond of the above-named results, namely, the greater uniformity in the character of the resultant product.

The application o f the wateralso decreases 'thetemperature at which the sintering is conducted below that 'which wouldexist as a result of the unmodified ornormal -eomb'ustion. This -is accompanied by ac'oo'ling and hence afcontractio'n of thevolume of' airl -`which .passes .through thev mass; Such .decrease in volum'eihenee permits of the em-v heit, so that the exhausting lapparatus-is op` .erated under com aratively low temperature conditions. D' culties 'heretofore experiployment of alower Vacuum in the exhaustl` ing .apparatus as above noted. The 'reduc-.l

enced` 4-in operating such ap aratus, and

chiey infconnection with the. earings,.are

The water being introduced directly upon the burning ore reduces -at `o nce the temperature Vof the ore b reason of the heat being abstracted direct y from thexbedof'fuel. This tends to check at once throughout the ore any volatilization of reducedmetal, or Eerhaps of the formed dioxid which might e carried, whenv volatilized, into the` `su porting bed and be deposedthere, or mig t be carried farther in.

The decrease in temperature is responsible 4for the fourth of the above-namedv results, namely, the retarding orelimination, of the burning out of the grate-bars. "In this manner, therefore, we

lent material in a manner more economical and more expeditious than has heretofore, insofar as we are aware been practised, and with results superior to thosewhichare ordinarily obtained'.

' 1Having we claim and esire to secure 'by Letters Pat-"` are enabled to carry out the process ofsinterin'g' pulveru-z los 1`. The methodof sint'ering ore/which consists in'establishin said're together with fuel v in a' layer "or i allowing-ignition. to. proceed until s'intering water to modify' the sintering.

- 10 consists in establishing said ore .together with BENJAMIN J. MULLEN. fuel in a layer or bed, igniting said ore, al- HARRY PEPPEL.

lowing ignition to proceed until sintering Attested byconditions havefbeen established, and sup- E. V. WARREN,

2. The method of sinteringne ore which liquid in quantity suiiicient to maintain sin! ab consists in establishing said ore together tering conditions. t yvth fuel lin a layer or bed, idgniting said ore, Signed by me, this 13th day of Sept., 1913;

a owing. ignition to procee until sinterin i 5 conditions have been established, and supplyg: Attest d b MAX MCM-URRAY ing then directly upon the ignited ore, water e y quantity sufficient to maintain sintering conditions.

4 3. The method of sintering iin'e ore which F. C. KETTRING, R. C. FARQUHAR. y Signed by '11s, this 16 day of Sept.,'l913.

plying then directly upon the ignited ore, a VFRIEDA CHnLLIs. 

